WO 2011/006469 A1 sets out a multiple-part piston for an internal combustion engine and a method for producing such a piston. The method for producing a multiple-part piston for an internal combustion engine comprises the following method steps: producing an upper piston portion and a lower piston portion each having an inner support element having joining faces and an outer support element having joining faces, applying a high-temperature solder material in the region of at least one joining face, assembling the upper piston portion and the lower piston portion to form a piston member by producing contact between the joining faces, bringing the piston member to a vacuum furnace and evacuating the vacuum furnace, heating the piston member at a pressure of a maximum of 10−2 mbar to a soldering temperature of a maximum of 1300° C. and cooling the soldered piston at a pressure of a maximum of 10−2 mbar until complete hardening of the high-temperature solder material. WO 2011/006469 A1 further relates to a multiple-part piston which can be produced with this method for an internal combustion engine, in which annular inner support elements which delimit an outer peripheral cooling channel and an inner cooling chamber are provided.
DE 10 2008 038 325 A1 proposes a method for fixing an annular element to a piston for an internal combustion engine, in which the annular element is screwed onto the piston base member by means of a thread which is fitted to the radial outer face of a portion of the piston base, an upwardly open, peripheral groove is formed in the piston base in the region of the thread, the groove is filled with solder material, the piston is heated until the solder material fluidizes and flows between the thread turns of the thread, and subsequently the piston is cooled. There is thereby produced a screw connection between the piston base member and the annular element. A screw connection requires additional components and is time-consuming to produce.
Welding (laser welding, friction welding) for joining the lower portion and upper portion to form a piston including stress-free annealing with subsequent, additional heat treatment (quenching and tempering) is time and cost-intensive.
In the prior art, in one operating step the formation of the materially engaging connection is carried out between the lower portion and the upper portion of a piston blank or piston, in particular as a solder connection. In at least one additional operating step, the heat treatment is carried out to form the provided ferritic/carbidic structure, the quenching and tempering. This requires a double introduction of heat into the piston structure and is time-consuming.